Fix PMD findings.

Author: phipag

powertools-metrics/src/main/java/software/amazon/lambda/powertools/metrics/internal/RequestScopedMetricsProxy.java

@@ -18,6 +18,7 @@
 import java.util.HashMap;
 import java.util.Optional;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Consumer;
@@ -33,7 +34,7 @@
 
 public class RequestScopedMetricsProxy implements Metrics {
     private static final String DEFAULT_TRACE_ID = "DEFAULT";
-    private final ConcurrentHashMap<String, Metrics> metricsMap = new ConcurrentHashMap<>();
+    private final ConcurrentMap<String, Metrics> metricsMap = new ConcurrentHashMap<>();
     private final MetricsProvider provider;
     private final AtomicReference<String> initialNamespace = new AtomicReference<>();
     private final AtomicReference<DimensionSet> initialDefaultDimensions = new AtomicReference<>();

powertools-metrics/src/test/java/software/amazon/lambda/powertools/metrics/ConfigurationPrecedenceTest.java

@@ -33,8 +33,8 @@
 import com.fasterxml.jackson.databind.ObjectMapper;
 
 import software.amazon.lambda.powertools.common.internal.LambdaHandlerProcessor;
-import software.amazon.lambda.powertools.metrics.model.MetricUnit;
 import software.amazon.lambda.powertools.common.stubs.TestLambdaContext;
+import software.amazon.lambda.powertools.metrics.model.MetricUnit;
 
 /**
  * Tests to verify the hierarchy of precedence for configuration:
@@ -44,7 +44,7 @@
  */
 class ConfigurationPrecedenceTest {
 
-    private final PrintStream standardOut = System.out;
+    private static final PrintStream STANDARD_OUT = System.out;
     private final ByteArrayOutputStream outputStreamCaptor = new ByteArrayOutputStream();
     private final ObjectMapper objectMapper = new ObjectMapper();
 
@@ -65,7 +65,7 @@ void setUp() throws Exception {
 
     @AfterEach
     void tearDown() throws Exception {
-        System.setOut(standardOut);
+        System.setOut(STANDARD_OUT);
 
         // Reset the singleton state between tests
         java.lang.reflect.Field field = MetricsFactory.class.getDeclaredField("metricsProxy");
@@ -183,7 +183,7 @@ void shouldUseDefaultsWhenNoConfiguration() throws Exception {
         assertThat(rootNode.has("Service")).isFalse();
     }
 
-    private static class HandlerWithMetricsAnnotation implements RequestHandler<Map<String, Object>, String> {
+    private static final class HandlerWithMetricsAnnotation implements RequestHandler<Map<String, Object>, String> {
         @Override
         @FlushMetrics(namespace = "AnnotationNamespace", service = "AnnotationService")
         public String handleRequest(Map<String, Object> input, Context context) {
@@ -193,7 +193,8 @@ public String handleRequest(Map<String, Object> input, Context context) {
         }
     }
 
-    private static class HandlerWithDefaultMetricsAnnotation implements RequestHandler<Map<String, Object>, String> {
+    private static final class HandlerWithDefaultMetricsAnnotation
+            implements RequestHandler<Map<String, Object>, String> {
         @Override
         @FlushMetrics
         public String handleRequest(Map<String, Object> input, Context context) {

powertools-metrics/src/test/java/software/amazon/lambda/powertools/metrics/MetricsBuilderTest.java

@@ -35,7 +35,7 @@
 
 class MetricsBuilderTest {
 
-    private final PrintStream standardOut = System.out;
+    private static final PrintStream STANDARD_OUT = System.out;
     private final ByteArrayOutputStream outputStreamCaptor = new ByteArrayOutputStream();
     private final ObjectMapper objectMapper = new ObjectMapper();
 
@@ -46,7 +46,7 @@ void setUp() {
 
     @AfterEach
     void tearDown() throws Exception {
-        System.setOut(standardOut);
+        System.setOut(STANDARD_OUT);
 
         // Reset the singleton state between tests
         java.lang.reflect.Field field = MetricsFactory.class.getDeclaredField("metricsProxy");

powertools-metrics/src/test/java/software/amazon/lambda/powertools/metrics/MetricsFactoryTest.java

@@ -41,7 +41,7 @@ class MetricsFactoryTest {
     private static final String TEST_NAMESPACE = "TestNamespace";
     private static final String TEST_SERVICE = "TestService";
 
-    private final PrintStream standardOut = System.out;
+    private static final PrintStream STANDARD_OUT = System.out;
     private final ByteArrayOutputStream outputStreamCaptor = new ByteArrayOutputStream();
     private final ObjectMapper objectMapper = new ObjectMapper();
 
@@ -62,7 +62,7 @@ void setUp() throws Exception {
 
     @AfterEach
     void tearDown() throws Exception {
-        System.setOut(standardOut);
+        System.setOut(STANDARD_OUT);
         System.clearProperty(LambdaConstants.XRAY_TRACE_HEADER);
 
         // Reset the singleton state between tests

powertools-metrics/src/test/java/software/amazon/lambda/powertools/metrics/internal/LambdaMetricsAspectTest.java

@@ -41,7 +41,7 @@
 
 class LambdaMetricsAspectTest {
 
-    private final PrintStream standardOut = System.out;
+    private static final PrintStream STANDARD_OUT = System.out;
     private final ByteArrayOutputStream outputStreamCaptor = new ByteArrayOutputStream();
     private final ObjectMapper objectMapper = new ObjectMapper();
 
@@ -62,7 +62,7 @@ void setUp() throws Exception {
 
     @AfterEach
     void tearDown() throws Exception {
-        System.setOut(standardOut);
+        System.setOut(STANDARD_OUT);
 
         // Reset the singleton state between tests
         java.lang.reflect.Field field = MetricsFactory.class.getDeclaredField("metricsProxy");
@@ -216,7 +216,7 @@ void shouldUseCustomFunctionNameWhenProvidedForColdStartMetric() throws Exceptio
         JsonNode dimensions = coldStartNode.get("_aws").get("CloudWatchMetrics").get(0).get("Dimensions").get(0);
         boolean hasFunctionName = false;
         for (JsonNode dimension : dimensions) {
-            if (dimension.asText().equals("FunctionName")) {
+            if ("FunctionName".equals(dimension.asText())) {
                 hasFunctionName = true;
                 break;
             }